From 1d33ea81beccbaebe2f7524e156c3d319a48afad Mon Sep 17 00:00:00 2001
From: MarekSpodBiedry <73122968+MarekSpodBiedry@users.noreply.github.com>
Date: Sat, 10 Oct 2026 19:06:52 +0200
Subject: [PATCH] Write comment and hyperlink maps with A1 keys so JSON save
 works (#126)

---
 crates/engine/src/tests.rs  | 17 +++++++++++++
 crates/model/src/cellmap.rs | 51 +++++++++++++++++++++++++++++++++++++
 crates/model/src/lib.rs     |  1 +
 crates/model/src/sheet.rs   |  2 ++
 4 files changed, 71 insertions(+)
 create mode 100644 crates/model/src/cellmap.rs

diff --git a/crates/engine/src/tests.rs b/crates/engine/src/tests.rs
index b6caa09b4..a2ae4be0e 100644
--- a/crates/engine/src/tests.rs
+++ b/crates/engine/src/tests.rs
@@ -1018,3 +1018,20 @@ fn malformed_xlsb_keeps_the_current_workbook() {
     assert_eq!(v(&s, "A1"), Value::from("Keep me"));
     assert!(s.doc().unwrap().is_dirty());
 }
+
+#[test]
+fn notes_comments_and_links_survive_a_json_save() {
+    let mut s = s();
+    s.execute("cell.set", json!({"cell": "A1", "input": "x"})).unwrap();
+    s.execute("review.newNote", json!({"cell": "A1", "text": "note", "author": "Example"})).unwrap();
+    s.execute("review.newComment", json!({"cell": "B2", "text": "comment", "author": "Example"})).unwrap();
+    s.execute("insert.link", json!({"cell": "C3", "target": "Sheet1!A1", "tooltip": "jump"})).unwrap();
+    let wb = &s.doc().unwrap().wb;
+    let bytes = crate::io::save_bytes(wb, "book.json").unwrap();
+    let (back, _) = crate::io::open_bytes("book.json", &bytes).unwrap();
+    let (before, after) = (wb.active().unwrap(), back.active().unwrap());
+    assert_eq!((before.comments.len(), before.hyperlinks.len()), (2, 1));
+    assert_eq!(after.comments, before.comments);
+    assert_eq!(after.hyperlinks, before.hyperlinks);
+    assert_eq!(after.cells, before.cells);
+}
diff --git a/crates/model/src/cellmap.rs b/crates/model/src/cellmap.rs
new file mode 100644
index 000000000..6bfd1dea1
--- /dev/null
+++ b/crates/model/src/cellmap.rs
@@ -0,0 +1,51 @@
+//! Serde helpers for maps keyed by `CellRef`. JSON object keys must be strings, so the keys are
+//! written as `A1`-style text.
+
+use std::collections::BTreeMap;
+
+use gridcraft_core::CellRef;
+use serde::de::Error;
+use serde::{Deserialize, Deserializer, Serialize, Serializer};
+
+pub fn serialize<S: Serializer, V: Serialize>(map: &BTreeMap<CellRef, V>, s: S) -> Result<S::Ok, S::Error> {
+    s.collect_map(map.iter().map(|(k, v)| (k.a1(), v)))
+}
+
+pub fn deserialize<'de, D: Deserializer<'de>, V: Deserialize<'de>>(d: D) -> Result<BTreeMap<CellRef, V>, D::Error> {
+    let raw = BTreeMap::<String, V>::deserialize(d)?;
+    let mut out = BTreeMap::new();
+    for (k, v) in raw {
+        let cell = CellRef::parse(&k).ok_or_else(|| D::Error::custom(format!("invalid cell reference `{k}`")))?;
+        out.insert(cell, v);
+    }
+    Ok(out)
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::{Comment, Hyperlink, Sheet};
+    use gridcraft_core::CellRef;
+
+    #[test]
+    fn comments_and_hyperlinks_survive_json() {
+        let mut s = Sheet::new("S");
+        let a1 = CellRef::new(0, 0);
+        let c3 = CellRef::new(2, 2);
+        s.comments.insert(
+            a1,
+            Comment {
+                author: "Example".into(),
+                text: "note".into(),
+                replies: vec![("B".into(), "r".into())],
+                threaded: true,
+                resolved: false,
+                visible: false,
+            },
+        );
+        s.hyperlinks.insert(c3, Hyperlink { target: "Sheet1!A1".into(), tooltip: Some("jump".into()) });
+        let json = serde_json::to_string(&s).expect("serialize");
+        let back: Sheet = serde_json::from_str(&json).expect("deserialize");
+        assert_eq!(back.comments, s.comments);
+        assert_eq!(back.hyperlinks, s.hyperlinks);
+    }
+}
diff --git a/crates/model/src/lib.rs b/crates/model/src/lib.rs
index ba0f32c43..57b8d05d0 100644
--- a/crates/model/src/lib.rs
+++ b/crates/model/src/lib.rs
@@ -6,6 +6,7 @@
 
 mod b64;
 pub mod cell;
+mod cellmap;
 pub mod features;
 pub mod sheet;
 pub mod store;
diff --git a/crates/model/src/sheet.rs b/crates/model/src/sheet.rs
index 4b4200d39..2e33f3441 100644
--- a/crates/model/src/sheet.rs
+++ b/crates/model/src/sheet.rs
@@ -48,7 +48,9 @@ pub struct Sheet {
     pub validations: Vec<Validation>,
     pub tables: Vec<Table>,
     pub autofilter: Option<AutoFilter>,
+    #[serde(with = "crate::cellmap")]
     pub comments: BTreeMap<CellRef, Comment>,
+    #[serde(with = "crate::cellmap")]
     pub hyperlinks: BTreeMap<CellRef, Hyperlink>,
     pub charts: Vec<Chart>,
     pub images: Vec<Image>,